WASHINGTON -- With the U.S. Department of Justice's approval, Georgia now has one of the toughest voter verification and ID systems in the country.

Last week the Justice Department abruptly ended years of legal fights with the state and gave its approval to Georgia's policy of checking the citizenship of people who register to vote for the first time against driver's license and Social Security records. Georgia is one of only two states -- the other being Arizona -- that has such as policy.

State officials and other proponents of the voter registration verification program say it's needed to keep illegal immigrants from breaking the law and casting votes. Voting rights and minority group advocates say Georgia's system could hinder minorities who are legal citizens from voting.

Either way, the voter verification program will have implications for elections in Georgia -- and perhaps other states as well, elections experts say.

In the short term, it could create obstacles for those registering to vote for the first time -- and more headaches for local elections officials who must ultimately ensure they are citizens. Voters whose citizenship status gets flagged by the system will have to prove they are Americans by providing birth certificates, passports or other documentation. More than 4,200 prospective voters were flagged by the system before the July primaries.

There is sharp debate over the impact of the verification policy: Critics say it can discourage minorities from voting, particularly among Georgia's growing number of Latino an Asian residents. Proponents say it will have no effect on legitimate Georgia voters but will prevent voting fraud by illegal immigrants.

"Every time someone who is not a U.S. citizen votes, it steals the vote of a legitimate and eligible U.S. citizen," said Hans von Spakovsky, a former federal and Fulton County elections official who now studies voting issues for the conservative Heritage Foundation in Washington. "This isn't going to have any effect on [voter] turnout, but what it is going to do is be effective in preventing people who are noncitizens from voting."

That was the thinking behind why Georgia two years ago began matching voter registration records with driver's license and Social Security data to try to keep illegal immigrants from voting. The voter verification system was designed under the federal Help America Vote Act. The Justice Department in 2008, then under Republican President George W. Bush, first questioned the system and said federal law required the state to verify a voter's identity, but not his or her citizenship.

One study has shown instances of voter fraud by noncitizens are almost nonexistent nationwide, said Justin Levitt, an elections researcher and law professor at Loyola Law School in California. In a 2007 study he did for the Brennan Center for Justice, Levitt looked at thousands of cases of alleged voting fraud by noncitizens across the country.

In most cases, the allegations stemmed from mistakes in data comparisons, or in very rare cases some noncitizens said they mistakenly voted because they thought they were allowed to do so. Levitt's study did not document any cases of noncitizens either intentionally registering to vote or voting with the knowledge that they were ineligible.

Levitt said that people in the country illegally usually try to avoid paper trails like voting records they know could get them kicked out of the country.

"It just doesn't make a whole lot of sense that someone would feel so passionate about [casting a vote] that they'd subject themselves to a $10,000 fine, a 10-year prison term and deportation," he said.

Georgia and Arizona aside, most states simply require people to declare that they're citizens in order to register to vote, and face severe penalties if they're caught lying.

Levitt and others say voter verification systems like Georgia's and Arizona's do more to suppress legitimate voters than to identify potential fraud by noncitizens.

"Voter fraud is a very minor problem -- disenfranchisement [of legitimate voters] is a much bigger risk," said Toby Moore, an elections researcher at RTI International. RTI is a nonpartisan research institute based in North Carolina's Research Triangle with offices in Atlanta.

The problem with requiring people to provide proof of citizenship is that not all citizens have such proof, Levitt said. A relatively small percentage of Americans have passports, and birth certificates get lost, he said. And if you're older or born in a rural area or at home instead of a hospital, you might not have a birth certificate at all.

Georgia Secretary of State Brian Kemp, who supervises the state's elections, and Gov. Sonny Perdue have vigorously defended the voter verification system.

"Georgia has worked diligently to uphold the sanctity of the ballot box," Perdue said in a statement last week. "To ensure honest and fair elections, we must provide access to all eligible voters and make certain that all who cast a vote are eligible."

Minority group advocates don't disagree, but they say requiring some citizens to prove their citizenship is both discriminatory and discouraging.

Jerry Gonzales, executive director of the Georgia Association of Latino Elected Officials, said many Latinos who are legal U.S. citizens may opt not to even register to vote because of the potential hassles of proving their citizenship or fear of retribution to family members and friends who might be in the country illegally.

"There should be [fewer] barriers for citizens to exercise their right to vote, rather than more barriers," he said. "But based on what we've seen so far, this puts more obstacles and burdens on citizens to vote."

Moore, the elections researcher, suggested that other Republican-leaning states may follow Georgia's lead now that the voting verification system has the Justice Department's approval.

"Especially with immigration such a hot topic right now, a lot of Republicans think it's a winning issue for them," Moore said. "This is not going to open the floodgates ... but I think other states are going to take a fresh look at it."